[THRIFT-2955] Using list of typedefs does not compile on Go

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.2
• Fix Version/s: 0.9.3
• Component/s: Go - Compiler

Environment

Using golang 1.4 on linux/amd64

• Assignee: Jens Geyer
• Reporter: Johannes Martinsson
• Created: 28/Jan/15 12:51
• Updated: 22/Feb/17 21:01
• Resolved: 03/Feb/15 21:38

Description

Using a list with a typedefed value in a struct does not generate compilable
Go code.

Here is a small example definition which generates uncompilable code on at
least 0.9.2 and git master (as of the reporting of this issue).

Unable to find source-code formatter for language: thrift. Available languages are: actionscript, ada, applescript, bash, c, c#, c++, cpp, css, erlang, go, groovy, haskell, html, java, javascript, js, json, lua, none, nyan, objc, perl, php, python, r, rainbow, ruby, scala, sh, sql, swift, visualbasic, xml, yaml

namespace go poc
typedef i64 X
struct Y {
	1: list<X> xs
}

I've extracted some of the relevant snippets of code from the generated Go
code.

type X int64

type Y struct {
	Xs []int64 `thrift:"xs,1" json:"xs"`
}

func (p *Y) ReadField1(ipot thrift.TProtocol) error {
	tSlice := make([]int64, 0, size)
	for i := 0; i < size; i++ {
		var _elem0 X
		// _elem0 declared as X above
		// [...]
			temp := X(v)
			_elem0 = temp
		// [...]
		// Trying to append _elem0 (of type X) to p.Xs of type []int64
		p.Xs = append(p.Xs, _elem0)
	}
}

The issue is that the code is trying to append the typedefed type to a list of
the underlying type. I.e. appending X to a list of int64.

Smallest code change to make the generated code work is to cast _elem0 to
int64 in the append operation. However it might be better to actually
have p.Xs be of type []X rather than []int64.

(Currently I'm manually patching my generated Go code with type casts before appending to these lists.)

Issue Links

• is broken by: THRIFT-2793 Go compiler produces uncompilable code
• is depended upon by: THRIFT-4031 Go plugin generates invalid code for lists of typedef'ed built-in types